This paper deals with coordinated constructions of path phrases and seeks to establish a generalization which adequately describes the relevant phenomena. What is problematic in our attempts is a case of "double specification" which does not involve a coordinator. We elucidate this intriguing phenomenon, introducing notions such as a "complementary relation" and a "part-whole relation." A closer examination of this phenomenon reveals a second subtype which is to be subsumed under the same category. Lastly, we tackle a more fundamental issue of coordination in general-why use a coordinator to express semantic coordination? A dual function of the coordinator holds the key to the solution: a linking and a separating function.